Indicator mechanism for internal combustion engines



l W. M. KAUFFMANN 1,972,228

INDICATOR MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed March 31, 1933 2 Sheets-Sheet l I 30 H o p 1934- w. M. KAUFFMANN 1,972,228

INDICATOR MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed March 31, 1933 2 Sheets-Sheet 2 IN VEIVTOR. WWI 007 p7 160 70700/1 B Y A YTORNE Y5.

Patented Sept. 4, 1934 UNITED STATES INDICATOR MECHANISM FOR INTERNAL COMBUSTION ENGINES William M. Kauffmann,

Oil City, Pa., assignor to National Transit Pump '& Machine Company,

Oil City,

Application March 31,

3 Claims.

My invention relates to indicator mechanisms and particularly to indicator mechanisms for multiple cylinder internal combustion engines.

An object of my invention is to provide an indicator mechanism that may be easily and conveniently attached to a rotatable element of an engine to provide suitable mechanical connections to the usual recording mechanism.

A further object of my invention is to provide an arrangement whereby connections between a moving engine'member and therecording mechanism may be made or broken easily and safely while the engineis in rapid operation.

A further object of my invention is to provide an arrangement whereby the operating mecha nism connected to an engine to be tested may be easily and quickly adjusted to positions corresponding to the various cylinders the performance of which is to be tested.

In accordance with the present invention I provide operating mechanism comprising a plate that is adapted to be connected to th end of the crank shaft of the usual multiple cylinder gas engine. A crank member which is carried by M the plate may be adjusted angularly to any one of a number of positions corresponding to the positions of the pistons of the several cylinders of the engine. The motion of the crank during the rotation of the crank shaft provides a motion reducing mechanism for reciprocating a hook member in synchronism with the piston of the cylinder that is to be tested.

In order that the usual recording mechanism may be connected to and detached from the crank by means of the hook member while the engine is operating at relatively high speed, I provide a guide for the reciprocating hook member, the guide being slotted adjacent the path of movement of the hook member in such manner that a loop or hook connected to the usual cord for the recording mechanism may be inserted therein without danger to the operator and with the assurance that the desired mechanical connections to the hook member will be made.

The details of my invention will be described in connection with the accompanying drawings in which Fig. l is an elevational View of the assembled indicator mechanism with the recording mechanism connected to the operating mechanism therefor; Fig. 2 is an enlarged fragmentary View of the slotted hook guide; Fig. 3 is a front elevational view of the operating mechanism for the recording mechanism; Fig. 4 is a view partly in longitudinal vertical section and partly in elevation of the mechanism of Fig. 3 and a portion of an engine crank shaft connected thereto, parts being broken away; Figs. 5 and 6 are enlarged side elevational views of the reciprocable hook member; and Fig. '7 is an enlarged perspective View Pa., a corporation of Pennsylvania 1933, Serial No. 663,767 (01. 234-24) of the loop attached to the cord of the recording mechanism.

Referring to the drawings the indicator mechanism comprises a plate 1 that is adapted to be bolted to the end of a crank shaft 2 of a multiple cylinder internal combustion engine which may be provided with six cylinders, by way of example, one of the cran is 3 of the crank shaft being shown. The plate 1 is connected to the crank shaft 2 by means of bolts 4, only one of which appears in Fig. 4.

The central portion of the plate 1 is provided with a boss 5 upon which is rotatably mounted an index plate 6 that is provided with a series of holes 7 arranged in a circle and corresponding in number to the number of cylinders of the engine. The index plate 6 is fixed in its angular position with respect to the plate 1 by means of a dowel pin 8.

A crank plate 9 that is concentric with the index plate 6 and is secured in position by means of a bolt 10 that extends into the boss 5, is provided with a tubular crank pin 11. The angular position of the crank plate 9 with respect to the index plate 6 is fixed by a spring pressed plunger 12 movable within the tubular bore of the crank pin 11 having at the outer end thereof a knob 13 by means of which the plunger 12 may be withdrawn from one of the holes '7 for adjustment to another hole '7 corresponding in position to that of the piston of the engine cylinder next to be tested. This crank provides a reduced motion mechanism that is in synchronism with the piston of the cylinder to be tested which operates through its pressure cycle during a complete revolution of the engine shaft 2.

A stationary flanged plate 14 that surrounds the mechanism at the end of the crank shaft 2 constitutes a support for a hollow cylindrical guide 15 within which is mounted a reciprocable rod 16 that is secured to the crank pin 11 by means of a connecting rod 17 and a pivot pin 18. The plate 14 may be secured to any suitable stationary portion of the engine structure.

As is best shown in Figs. 4, 5 and 6 the rod 16 is provided with a relatively long cut-out portion 19 which extends from a hook 20 at the top thereof to an intermediate bevelled portion 21. The vertical guide 15 is provided with a relatively short transverse slot 22 from the inner ends of which extend two oppositely disposed vertical slots 23 connected thereto. The slots 23 are adjacent and substantially coextensive with the path of movement of the hook 20.

The recording mechanism, which is illustrated in Fig. 1, and the details of which constitutes no part of the present invention, comprises a usual drum or cylinder 25 that is adapted to receive the paper or other material upon which the pressure diagram is to be recorded. The drum 25 is mounted for rotation by means of a cord 26 wound its around a grooveddrum 27 at the bottom thereof. A spring 28 which is shown by way of example as a torsion spring, retu'rns'the drum 25 to its normal position by reason of the stress under which the spring is placed when the cord is operated by the engine. A pen or stylus 29 for marking the diagram on the paper on the drum is carried by a lever arm 30 that is connected to a link mechanism 31. The arm 30 is actuated by a piston 32 of a cylinder 33 that is responsive to the pressure of the engine cylinder being tested as transmitted to the piston 32 through a suitable pipe as. The latter may be connected to the engine cylinder in any usual or suitable manner. A spring 35 returns the piston 32 to its illustrated position upon release of pressure applied to the cylinder 33.

. The cord 26 is provided at the end thereof with a hook or loop 36 of wire or metal that is of such width that it is adapted to be inserted through the slot 22 into the slots 23 and into engagement with the hook 20. When the loop 36 is inserted in the transverse slot 19 against the cut-away portion of the reciprocating rod 15 the loop 36 may be released regardless of the position of the hook 20 and the engagement of these members will be assured since the force of the spring 28 causes the loop 36 to be drawn upwardly in the slots 23 until it engages the hook 20. This engagement will occur regardless of the speed of operation of the engine and accordingly of the reciprocation of the rod 16.

It may be assumed that the engine, the cylinders of which are to be tested, is inoperation and that the crank shaft 2,'together with the rotatable mechanism including'the plate 1, index plate 6 and crank plate 9 are rotating. Therod 16 is accordingly reciprocating in accordance with the speed of the engine through a path the length of which is determined by the throw of the crank pin 11. It may be assumed that it is desired to secure a pressure diagramof the cylinder of the engine corresponding to the position of the crank pin 11. v V

The drum 25 is provided'with paper of suitable size and character for recording the pressure diagram, and the loop 36 is inserted into the slot 22 of thehookguide 15 for engagement by the hook 20. The downward movement of the hook 20 causes the cord 26 to rotate the drum 25 and at the same time variation in the pressure of the cylinder causes the stylus 29 to correspondingly vary its vertical position. 1 e spring 28 returns the drum to its initial position when the hook moves upward. The result is to produce a diagram the shape of which indicates the pressures in the cylinder being tested at the various portions of its stroke during its working cycle. a

The engine is then stopped and the loop 36 is removed from its engagement with the hook 20. The recording mechanism is prepared for a similar test of another cylinder, if desired.

In order to adjust'the operating mechanism for another cylinder the bolt 10 is loosened and the knob 13 ispulled outwardly to remove the plunger 12 a sufiicient distance to permit the rotation of the crank plate 9 and crank pin 11. The crank plate 9 is adjusted with the plunger 12 in alignment with a second hole '7 that'cor responds to the position of the piston of the cyl-.

inder to be tested and the bolt 10 is again tights ened. When these adjustments have been made the operating mechanism is in readiness for testing the cylinder corresponding to the position of the crank pin 11.

The engine is then started and when it is in normal operation the loop 36 of the cord 26 is example only and that the mechanism may beadapted for any desired number of cylinders.

The advantages of the indicator mechanism of my invention are that it may be easily and conveniently attached to the crank shaft of internal combustion engines, and that the rotation of the crank through a circle of relatively small diameter eliminates the necessity of providing special mechanism for reducing the motion of the pistons'of the engine-to a degree that is within the limits of the recording mechanism. It will be appreciated also that the adjustment of the operating mechanism from one cylinder to another may be made quickly and by the manipulation of relatively few parts.

The provision of the hook guide with its entrance slot and longitudinal slot adjacent the path of movement of the hook portion for engaging the loop of the cord enable the operator to safely and conveniently connect the recording mechanism to the operating mechanism of the indicator while the engine is in rapid motion. Also, if desired, the loop of the cord may be disconnected from the hook 20 andremoved from the guide 15 while the engine is running.

I claim: a

1'. Indicator mechanism comprising a reciprocable member operable in synchronism with the piston of a cylinder to be tested, said member having a hook thereon, a stationary guide for said member having a slot therein, and means adapted to extend through said slot for engage ment by said hook forreciprccation therewith.

2. Indicator mechanism comprising a reciprocable member operable in synchronism with the piston of a cylinder to be tested, member having a hook thereon, a stationary guide for said member having a slot extending transversely through a wall of said guide and having other slots communicating with the transverse slot and extending longitudinally of said guide, and a member having a loop for insertion through the transverse slot for reciprocation with said hook in the longitudinal slots. Y

3. Indicator mechanism comprising a reciprocable member having a hook, a stationary tubular guide for said member having a slot extending transversely through a wall thereof and extending longitudinally of said guide adjacent the path of movement of said hook on opposite sides of said hook, said slot being adapted to receive a recording mechanism actuating member for engagement by said hook and for reciprocation with the latter in the longitudinal portions of the slot.

WILLIAM M. KAUFFMANN. 

